Goals and Objectives In response to the reviewers comments from the Summary Statement for the prior submission of this application (February 2008), the stopped-flow spectrophotometer has been removed from this Facility Core and is now considered part of a departmental resource available through Biochemistry and no longer supported by the P30 EHS Core Center. It should also be noted that due to the no-cost extension of this grant (04/01/09-03/31/10), no financial support will be provided to the Structural Biology Facility Core by the P30 EHS Core Center until funding of the grant is renewed. Work related to the individual research grants of Center Investigators will continue, but user fees will be charged to other sources. The Structural Biology Facility Core provides users from the P30 EHS Core Center with access to state-of-the-art nuclear magnetic resonance (NMR) instrumentation and X-ray crystallography. With the expertise of Facility Core personnel, this instrumentation is used to delineate the consequences of toxicological insults to cells at the molecular level and to develop experimental methods that further the research objectives of the P30 EHS Core Center The instrumentation is operated by the university-wide structural biology program, directed by Prof. Walter Chazin (Dept. Biochemistry and Center in Molecular Toxicology Investigator) and is operated jointly as a Facility Core of the P30 EHS Core Center. Physically, most of the NMR instrumentation is housed in the Stevenson Building, with one spectrometer located in the newly constructed Medical Research Building IV. Crystallography equipment is housed in Medical Research Building III and in the Robinson Research Building. All of these facilities are located on the Vanderbilt University campus within easy walking distance. Much of the crystallography data collection actually takes place at the synchrotron facilities located at Argonne National Laboratory. The Structural Biology Facility Core accommodates analytical needs in NMR spectroscopy and complex studies in structural biology and plays a prominent role in the research efforts of Center Investigators.